Tandem ink cartridges for ball point pens



Nov. 9, 1965 A. WASHCALUS 3,216,398

TANDEM INK CARTRIDGES FOR BALL POINT PENS Filed Sept. 26, 1962 IN VENTOR.

7 /0 5 AMSA/C'AZ 0s HTTOR/Vf) United States Patent 3,216,398 TANDEM INK CARTRIDGES FOR BALL POINT PENS Thomas A. Washcalus, Plymouth, Pa., assignor to Eberhard Faber Inc., Wilkes-Barre, Pa., a corporation of New York Filed Sept. 26, 1962, Ser. No. 226,314 3 Claims. (Cl. 120-421) This invention relates to writing implements. More particularly the invention relates to writing implements employing a pair of tubular ink cartridges each provided with a ball point writing tip at one end and an open end at the other with the cartridges so mounted in the pen barrel that the writing tip is automatically retractable.

In its more specific aspect, the invention contemplates a writing implement in which a plurality of ink cartridges are connected in axial alignment within the implement in such way that air may communicate with the open ends of the cartridges at all times.

It is an object of the invention to provide an ink cartridge for ball point pens comprising a pair of aligned cartridge sections having a ball point writing end and an opposite open end, with the sections connected in tandem by a vented plug which extends into the open ends of the sections and which is elfective to connect the sections with the ball point writing ends at opposite ends of the assembly.

It is a further object of the invention to provide an ink cartridge assembly composed of a pair of axially connected cartridge sections, each having a tubular ink chamber terminating in a portion of reduced diameter at the writing end and forming thereby an external shoulder at the junction of the portion of reduced diameter and the ink chamber which forms an eflective stop for a tubular point protecting structure.

It is a still further object of the invention to provide a writing implement having a tandem ink cartridge assembly which has writing points at its opposite ends, and which has a cap for protecting the writing point at the inner end against damage by the mechanism ordinarily employed to project the outer end from the barrel of the pen.

It is a further object of the invention to provide a pair of co-axial ink cartridges for writing implements having means for adapting them to use in a great variety of makes and styles of pen barrels.

It is a further specific object of the invention to provide a protecting device for the ball point at the inner end of tandem ink cartridge assembly which may be readily segmented into sections of predetermined lengths to adapt the ink cartridge assembly to the variation in the lengths of pen barrels of :diiferent styles and manufacture.

These and other objects and advantages of the invention will become clear as the description thereof is read in light of the drawings. In the drawings, like reference numerals indicate like parts, and

FIG. 1 is an elevational View of a ball point pen assembly according to the present invention, the ink cartridge thereof comprising a first and second section and the pen barrel being shown in dot-and-dash lines;

FIG. 2 is an elevational view of the tandem ink cartridge assembly showing parts in cross-section to more clearly show underlying structure;

FIG. 3 is a perspective view of a connecting plug useful in joining a pair of ink cartridges in tandem arrangement;

FIG. 4 is a perspective view of a connecting plug of modified form;

FIG. 5 is a perspective view of a tubular cartridge tip protector; and

FIG. 6 is a perspective view of a cartridge tip protector of modified form.

In its more particular aspect, the invention comprises a pair of ink cartridge sections 10 and 12 each having a ball point Writing end 14 and 16. Each section provides a tubular ink chamber which terminates in a portion of reduced diameter 18 and 20 respectively, the portion of reduced diameter being formed at the writing end of the cartridge section and providing thereat an external shoulder at the junction of the portion of reduced diameter and the ink chamber. The aligned cartridge sections 10 and 12 are connected at their normally open end by means of a connecting plug which extends into the confronting open ends of the two sections and which engages the inner surfaces of the cartridge walls in sufliciently tight engagement to connect the sections 10 and 12 in tandem with the respective ball point writing ends 14 and 16 at opposite ends of the assembly.

The connecting plug is characterized by means for positively spacing the confronting ends of the cartridges and by means for venting the interior of the cartrdiges. The plug may be embodied in a variety of difierent forms, for example, those shown in FIGS. 3 and 4.

As more particularly shown in FIG. 3, the plug 22 has a pair of laterally extending portions 24 and 26 in the form of a pair of ears extending outwardly from opposite diameters thereof. The ears 24 and 26 constitute spacing abutments for the connected inner ends of the aligned ink cartridge sections. The spacing means of the connecting plug 23, shown in FIG. 4, comprises a raised circumferential band 25.

It is desirable to vent the ink cartridges to the atmosphere in order to avoid a sub-atmospheric condition on the top of the ink column which would result in stoppage of ink flow to the writing end of the cartridge. To the end that the cartridge sections may be properly vented, the connecting plug is formed with an axial groove which constitutes a vent formed along the axial surface of the plug. In FIG. 3 the venting groove is identified by the reference numeral 28, which in FIG. 4 it is identified by the numeral 29.

Since the confronting normally open ends of the cartridge sections 10 and 12 cannot come into contact with each other by reason of the spacing projections on the connecting plug, the venting groove will concurrently serve to admit atmosphere to the top of the ink column in each of the cartridge sections.

The pen barrel 30 is shown in conventional form. It is intended that it be provided in any event with means for projecting and retracting the writing tip of the cartridge assembly. Each of the cartridge sections is slightly flattened to provide shoulders 32 and 34. These shoulders constitute abutments for a coil spring 36 which surrounds the lower cartridge section. The opposite end of the spring rests on a surface 38 at the forward end of the pen barrel 30. The spring 36 is under sufficient tension to hold the cartridge assembly retracted within the pen barrel unless it is held against retraction by one of the several generally conventional structures now commonly in use. Herein the projecting mechanism comprises a plunger 40 which extends through the rear end of the pen barrel and is guided in an aperture therein for reciprocation. The plunger 40 rests on the upper end of the car tridge assembly such that pressure tending to move the plunger inward will project the cartridge assembly against the tension of the spring 36. A leaf spring latch 42 is fixed to the plunger 40 and is formed with a downwardly extending projection 44 which is adapted to engage in a latching aperture 46 which is located in the pen barrel directly under the free end of the clip 48. Thus when the plunger 40 is pushed inwardly to compress the spring 36 and project the writing tip from the barrel, the latching projection 44 will engage in the aperture 46 and hold the entire assembly in projected position. In order to release the latching effect, it is merely necessary to depress the clip 48 such that its free end engages the projection 44 and pushes it back into the. aperture 46 to thereby release the same. Under these conditions the spring 36 will return the cartridge assembly to its retracted position.

This invention contemplates the' use of a ball point protector in the form of a sleeve which is assembled with the reduced end of the reserve ink cartridge. The sleeve is designed to perform two useful functions. In the first place, since the ball. 52 might, suffer damage as a resultof direct contact with the plunger 40 the sleeve, extending as it does, to a point somewhat beyond the writing tip of the cartridge section, provides a guard which protects the ball of the section against possible damage. The point protecting sleeve is preferably formed of a moldable plastic. material whicih is somewhat frangible.

It' is known that pen barrels vary in size and shape not only among the products of different manufactures but also among-various styles of the same manufacturer. It is of economic convenience to construct the ink cartridge, or ink cartridge assemblies, to fit a large variety ofpen barrels differing in size and shape from-each other. Consequently, theprotective sleeve herein can be provided in a variety of lengths, or can be easily segmented into sectionsto adapt it to better fit the length of. the pen barrel in whichthe cartridge is to be used.

In FIG. 4 the ball point protector isa simple tubular member 50 which is adapted to fit about the reduced end 18 of the reserve ink cartridge 10. It can be noted that it extends somewhat beyond the ball point 14 of the cartridge. In order to adapt the cartridge assembly to pen barrels which vary inlength, it is contemplated that protecting sleeves such as shownin FIG. be furnished in a variety of different lengths so that the purchaser has a choice of protectors. from among which he can select alength to properly adapt the cartridge assembly tothe particular length of the pen barrel in which it is to be used.

The above objective can also ,be accomplished by forming the protective sleeve as shown inFIG. 6. In that figure the sleeve 51is circumferentially scored at several points along its length, as by the spaced score lines 53 and 55. These score lines are preferably so spaced along thelengthof the sleeveas to afford sleeve segments that vary in length. whereby the purchaser may readily break the sleeve at a score line to provide one or more segments thereof for adapting. the cartridge assembly to the particular pen barrel in which it is to be used.

Resort to an axially arranged ink cartridge assembly composed of a plurality of sections or ink chambers greatly increases the life of a pen which is so constructed. n. t e ink in ne of the cart i sss a b en exhausted, it is merely necessary to separate the pen barrel at its screw-threaded joint 52, withdraw the cartridge assembly, reverse the ball point protecting sleeve to the reduced end of the now empty cartridge sections, reverse the assembly and reinsert it into the barrel. This results in an extension of the useful life of the pen and eliminates the need for cartridge replacement at very brief intervals.

While the fundamentally novel features of the invention have been illustrated and described in connection with a specific embodiment of the invention, it is believed that this embodiment will enable others skilled in the art to apply the principles of the invention in forms departing from the exemplary embodiment herein, and such departures are contemplated by the claims.

What is claimed is:

1. An ink cartridge assembly for use in ball point pens comprising a pair of aligned tubular cartridge sections, each having a ball point writing end and an opposite open end, and a connecting plug having an external surface adapted to frictionally engage within the open ends of said cartridge sections extending into the open ends of said sections effective to connect said sections in tandern with the ball point writing ends at opposite ends of the assembly, said plug having means intermediate of its ends extending laterally therefrom to form a spacing abutment for the connected ends of said sections whereby said sections are spaced from each other to provide for an air vent, and a channel formed along the entire axial surface of said plug providing an atmospheric vent to each of said cartridge sections.

2. The combination of claim 1, in which said spacing abutment means comprises a pair of. laterally extending ears and the said channel is formed in one of the plug surfaces between said pair of ears.

3. The combination of claim 1, in which said spacing abutment means comprises a circumferential surface, and said channel intersects said surface.

References Cited by the Examiner UNITED STATES PATENTS 2,803,219 8/57 Stoeberl -4203 2,829,623 4/58 Barnes 12042.03 2,972,335 2/61 Grube et al 120.42.1 3,018,761 1/62 Ashcroft 120-42.1

FOREIGN PATENTS 218,941 4/ 57 Australia. 1,228,971 3/60 France.

533,220 9/55 Italy.

EUGENE R. CAPOZIO, Primary Examiner.

LAWRENCE CHARLES, JEROME SCHNALL, LEONARD VARNER, Examiners. 

1. AN INK CARTRIDGE ASSEMBLY FOR USE IN BALL POINT PENS COMPRISING A PAIR OF ALIGNED TUBULAR CARTRIDGE SECTIONS, EACH HAVING A BALL POINT WRITING END AND AN OPPOSED OPEN END, AND A CONNECTING PLUG HAVING AN EXTERNAL SURFACE ADAPTED TO FRICTIONALLY ENGAGE WITHIN THE OPEN ENDS OF SAID CARTRIDGE SECTION EXTENDING INTO THE OPEN ENDS OF SAID SECTIONS EFFECTIVE TO CONNECT SAID SECTIONS IN TANDEM WITH THE BALL POINT WRITING ENDS AT OPPOSITE ENDS OF THE ASSEMBLY, SAID PLUG HAVING MEANS INTERMEDIATE OF ITS ENDS EXTENDING LATERALLY THEREFROM TO FORM A SPACING ABUTMENT FOR THE CONNECTED ENDS OF SAID SECTIONS 